Need help..

search: loud noise at start up' in the gen 2 forums.

it is likely hydrocarbons sitting on your intake manifold causing detonation. you could try the updated manifold, but i don't think it helps.

 

Welcome to PriusChat!!

Many DIY enthusiasts will include an OBD2 scanner in their arsenal of tools, if you want the best option for this vehicle, then buy a 'mini-vci' cable ($20) and install a copy of techstream (toyota dealer tech software) on a windows device. If you would rather try a more generic OBD2 option (may be useful for other applications), then buy a quality OBD2 bluetooth adapter and use an App like Dr Prius or Torque. Knowing the OBD2 codes (DTCs) may help diagnose the problem quicker. If you're able to retrieve the OBD2 codes, post them here for additional guidance and advice.

Which make/model spark plugs did you install?

You may have water in the spark plug well(s), has it been raining lately?

 

G2 Prius with very low miles on them have issues with the hybrid battery.
Start paying close attention to the charging and discharging behavior
of that battery on the mfd screen the screen above the radio.
See if it’s losing alot of charge from sitting. That could be why it’s not running good it has no power and what you call loud is you pushing the engine twice as hard to get anywhere because the majority of power comes from a healthy hybrid battery.
Thats stage1 of battery failure.

everyone’s hybrid battery is failing as we don’t drive much anymore.
Letting the car sit is death to that battery and the 12.

use the search forums link up top and search

hybrid battery

to see whatever one else is going through now.

 

Running VERY rough when started cold that then clears up completely after a short period can be a lot of things.......common to all engines.
But the Prius engines seem to have a tendency to accumulate oil in the intake manifold which gets sucked into the engine when first started.

I don't remember the exact cause....maybe EGR or PCV.

There are many threads about it, I just don't remember what key words to use to find them.
Hopefully someone else will remember.

 

Could.
How much more ? Could the oil level be low ??
Have you also noticed more "smoke" from the exhaust pipe when first started ?

 

Injectors? Or you burned all the oil and the engine is shot.

 

No you'll know if its throwing a code the dash will light up this car is not bashful about reporting issues.

I would move up to a thicker viscosity oil right now it will greatly help your oil issue. if your going through the trouble of replacing the plugs buy a valve cover gasket it will need it. Your in that area anyway its very easy to pull the valve cover and when its off its a great time to remove the pcv valve. Leave it in the cover take the cover off and then remove the pcv valve.
take pictures of the valve train and post them here. i want to see how it looks.

 

Wouldn't hurt. But whether it helps or not depends on exactly where and why the loss is occurring.
It might not help at all.

 

If you know 2-smokes, then you should be familiar with plug checks. How do they look?

 

Wheres the pictures? What makes you think the chain is worn out? Did not replace the pcv as i suggested real easy with the v cover off.

Want to see if its gunked up or the oil has been maintained. That's going to be the deciding factor if the chain is worn which at the mileage is highly unlikely. Issues with the chain are rare on a G2.

Probably just has a real dirty throttle body. In the picture of the throttle body you will see the 2 little hose connections. One is pretty clogged up thats the pcv hose connection. Both those hose inlets must be clean and the throttle bore clean like this one.

Also pictures of the chain at 145000 miles.